Ni-based catalysts derived from Ni-Zr-Al ternary hydrotalcites show outstanding catalytic properties for low-temperature CO2 methanation

Developing Ni-based catalysts with high activity and stability in low-temperature methanation is necessary due to their sintering and coking at high temperatures. Here, we report our developed novel Ni-Zr-Al catalysts derived from Ni-Zr-Al ternary hydrotalcites synthesized by a hydrothermal process, followed by a reduction in hydrogen. Comparing with the Ni-Al catalyst derived from Ni-Al hydrotalcite and the commercial Ni-based catalyst, the Ni-Zr-Al catalysts show a remarkably higher low-temperature activity (210−270 °C) in CO 2 methanation. Both the experimental and theoretical calculations confirmed the introduction of Zr into the Ni-Al binary hydrotalcite could generate synergetic effects between Ni and ZrO 2 , resulting in more surface oxygen vacancies, basic sites, and abundant mesopores . In-situ DRIFTS analysis showed the CO 2 methanation to CH 4 follows the intermediate formate route. This work provides a new theoretical understanding of CO 2 activation and methanation, and a practical way to address the existing problem for Ni-based catalysts.